Feeding mechanisms for sewing machines



Nov. 27, 1956 N. KNAUs ETAL FEEDING MECHANISMS FOR SEWING MACHINES FiledSept. 14, 1954 4 Sheets-Sheet l Fig.i

25 2| O I8 @n 2 5 #-5 27 L 58 34 M3/0657332855 e9 88 Fig .2 11W/15mm ndNicholaus Knaus WITNESS a Agnes G. Mllllngon BY W AToRNEY Nov, 27, 1956N. KNAUS ET AL 2,771848 FEEDING MEcHANIsMs FOR SEWING MACHINES FiledSept. 14, 1954 4 Sheets-Sheet 2 Fig .4 en 57 $556. lo? 87:"

5g 40 4o' 37 2z 38 55| Fug 52 INVENToR. and N/cho/aus Knaus WITNESS FgAgnes G. Millington MM d; BY

ATTORNEY Nov. 27, 1956 N. KNAUs ETAL 2,771,848

FEEDING MEcHANIsMs FOR SEWING MACHINES l Filed sept. 14, 1954 4sheets-sheet s INVENToR. and' Nicho/aus Knaus WITNESS Agnes G. Mi//ngfonwww BY W32! L. l AT ORNEY Nov. 27, 1956 N. KNAus ErAL 2,771,848

FEEDING MECHANISMS FOR SEWING MACHINES Filed Sept. 14, 1954 4Sheets-smeet 4 Inn 5 Fig iii 5 FULL? F ig.9

INVENTOR. and Ncho/aus .K'naus w/TNEss Agnes G, M//l/ngon /MM BY 2j ATRNEY FEEDNG NECHANISMS FOR SEWING MACHINES Nicholaus Knaus, Cranford,and Agnes G. Millington, Clifton, N. J., assignors to The SingerManufacturing Company, Elizabeth, N. J., a corporation of New JerseyApplication September 14, 1954, Serial No. 455,966

7 Claims. (Cl. 112-209) rl`his invention relates to feeding mechanismsfor sewing machines and more particularly to that type of feedingmechanism known as a differential feed in which two work-feedingelements are adapted to be actuated so as to exert unequal feedingactions on the work, thereby either to stretch or full the work asrequired.

The invention has as a primary object to provide an improved means foradjusting the length of feeding movement of one of a pair of four-motionfeed-dogs of a differential feeding mechanism during the operation ofsuch mechanism.

aired States Patent O A further object of the invention is to provideimproved after appear, the invention comprises the devices, combinationsand arrangements of parts hereinafter set forth and illustrated in theaccompanying drawings of a preferred embodiment of the invention fromwhich the several features of the invention and the advantages attainedthereby will be readily understood by those skilled in the art.

Fig. l represents an end elevation, partly in section, of an overseamingmachine showing the improved feeding mechanism.

Fig. 2 represents a sectional view taken substantially on the line 2--2of Fig. 1.

Fig. 3 represents a sectional view taken substantially on the line 3 3of Fig. l.

Fig. 4 represents a sectional view taken substantially on the line 4 4of Fig. l.

Fig. 5 represents a sectional view taken substantially on the line 5 5ofV Fig. 1.

Fig. 6 represents a sectional view taken substantially on the line 6 6of Fig. 4.

Fig. 7 represents a disassembled perspective view of the main andauxiliary feed-bars and their actuating means.

Fig. 8 represents an end elevation of an overseaming machine embodyingthe present invention and illustrates the machine with a portion of theframe end wall broken away so as to illustrate a portion of the treadlecontrol actuating means for the auxiliary feed-bar.

Fig. 9 represents a sectional view taken substantially on the line 9 9of Fig. 1.

Fig. 10 represents a sectional view taken substantially on the line 1(110 of Fig. 8.

Referring now to the drawings, the reference numeral denotes a frame ofan overseaming machine, 16 the head, and 17 a portion of the worksupport which is carried upon the frame in a conventional manner. Apresserfoot 18 is supported on the head 16 and the shank 19 of the footis engaged by -a spring-biased member 20 whereby the foot is normallypressed downwardly toward the work support 17. The rear 'portion of theshank 19 is mounted on a universal joint 21 in a conventional manner anda lever` 20 is provided for relieving the pressure of the spring-biasedmember 20.

ice

Treadle-actuated means, not herein shown, are provided for raising theshank 19 in opposition to the spring biased means 20 to permitintroduction or adjustment of the work beneath the presser-foot 18.Since this mechanism does not form the part of the present invention, acomplete disclosure thereof is not deemed necessary.

The machine is provided with a main rotary shaft 22 (see Fig. 3) whichis journaled in the frame 15, and the shaft through a link, not hereinillustrated, is connected with a needle-carrier 23 pivoted in a bushing24 so that the rotation of the shaft 22 effects the oscillation of thecarrier 23 within its bushing 24. A needle 25 is mounted in the carrier23 and the oscillation of the latter causes the needle to reciprocateand penetrate the goods that are supported upon the work support 17.Suitable stitch-forming implements or loopers cooperate with the needleto effect the formation of the overseaming stitches, but as theseloopers and the manner of and the means for actuating them form no partof the present invention, their illustration and further description arenot deemed necessary.

For a more complete description and illustration of the machine of thepresent type reference may be had to United States Patent No. 2,338,796,dated April 15, 1941.

kThe present work-feeding mechanism is of the differenti-al typeincluding a main feed-dog 26 and an auxiliary feed-dog 27 which aremounted, respectively, on the sideby-side main and auxiliary feed-dogcarriers or bars 28 and 29 slidingly supported at their forked rear ends30 and 31 upon blocks 32 and 33 (see Figs. 1 and 5). Each of theseblocks 32 and 33 is appropriately apertured so that to be snugly enteredand supported by a pin 34 which is force-fitted within an aperturedbushing 35 secured within a portion of the main frame 15. As will laterbe de scribed in more detail, the bars 28 and 29 are actuated in amanner such that they will both oscillate and move longitudinally aboutand relative to the pin 34 of which the longitudinal axis is common toboth of the feed-bars.

The feed-bars 28 and 29 receive their rising and falling movements froma feed-lift eccentric 36 carried by the main shaft 22; said eccentricbeing surrounded by the usual bearing block 37 which ts in ways 38and-39 formed in the feed-bars 28 and 29.

The feed and return movements are imparted to the main feed-bar 28 froma feed eccentric 40 removably and replaceably keyed upon the outer endof the main shaft 22 and held thereon by a nut 41 which is threaded overthe distal end portion 42 of the main shaft 22 spaced between theeccentric 40 and the feed-bar 28 is a conventional washer 40. The feedeccentric 40 is embraced by the apertured end portion 43 of a pitman 44which connects the eccentric 40 directly to the main feed bar 28 bymeans of a bolt 45 which passes through aperture 46 in the feed-bar 28and through the apertured rear end portion 47 of the pitman 44, whichbolt 45 is locked in position by means of a nut 48. A spacer sleeve 45is disposed over the bolt between the pitman 44 and the feed-bar 28.Thus rotation of the eccentric 40 will, through the medium of thepitman- 44, reciprocate the main feed-bar 28 back and forth lengthwiseof itself. Alteration of the amplitude of the feed return movements ofthe main feed-bar 28 is effected by substitution of feed eccentrics ofthe desired eccentricities, for that eccentric 40 illustrated in thepresent machine.

The pitman 44, together with its associated eccentric 40, are alsoadapted to impart feed and return movements `to the auxiliary feed 'bar29 through the medium of a rocker mechanism. This rocker mechanismcomprises a two-armed bracket (see Figs. l, 6 and 9) having'its arms v50and 51 secured to the machine base 15 by bolts 52. The free end portionsof thisl bracket are apertured as at 53 for rockably receiving therein ashaft 54 upon which is mounted a rock member generally designated by thenumeral 55. A set screw 55' locks the member 55 to the shaft 5d. Therock member 5S is formed with two arms 56 and 57 o which the latter isprovided with 'an `:extension 58 formed las an varcuate member orsegfment. The free end ,portion of the arm 56 is apertured a-s at 56'Vand is adapted to be connected by means 'of a v-'bolt 59 to-anapertured end portion v60 of a link 61 (see Figs. 2 and 7). The otherend portion of the link 61is apertured as at 461' and `is pivotallyconnectedto the main feedbar 2S by reason of the fact that it is mountedupon a cylindrical shoulder 62 formed upon the bolt 45 which, lashereinabove mentioned, is employed for securing `the fpitman=44 to themain feed-bar 2:8. From this it will y'be understood that as :the mainshaft 22 rotates the main :feed-bar A2S will be reciprocated ybackandforth by means 'of the .eccentric'dl and its associated :pitman 44, andthis vreciptocatory movement of .the main feed-bar 23 will .in'turnlfunction to reciprocate the Vlink 6l to the end that :the 'rocker55 will be oscillated about the longitudinal a-xisof its shaft 54.

Slidingly mounted upon and lengthwise of the rocker arm or segment S3-is a slide block generally designated by the numeral 63, ywhich slideblock has .projecting from the opposite sides thereof stub-shafts 64-64upon lwhich are mounted the opposite side portions -65 and 66 of atwo-part link member which in Fig. 4 is .designated generally by thenumeral 67. More specifically, each of the apertured end portions 625-68of the -link arms 65 .and 66 is adapted to be kpivotally mounted uponone'of thestub shafts 64 while the mid-portions of the two :frnem'bers65 and 66 are secured together `by means of a 'bolt 69 and an associatedspacer member 70. The other end portions of the members 65 Iand 66 carrya hollow sleeve 71 which projects through an aperture IZ formed inthemain feed-bar 2d so as to be secured to the auxiliary feed-hariw bymeans of a bolt 73 which is threaded directly -within -an aperture 74provided in the auxiliary feed-bar 29. rom this it is to be understoodthat the oscillating movements of the rocker` will, through therocker-arm 58 and the slide block-63, impart reciprocatory movements tothe link `member 67 which will in turn .effect endwise reciprocatorymovements in the auxiliary feed-bar 29.

The above noted slide block 63 comprises a U-shaped strap 75 havingconventional type convex shoes '76, 77 mounted therein for engaging .theopposite edge portions of the .rocker -arm 5S. The free end `portions ofthe U-.shaped strap 75 are closed -by a bolt `FIS and a spacer sleeve79.

As it may oe best observed in Figs. 1, '5 and 7, one of the hollow stubshafts 65. of the slide block 63 is elongated for the purpose of havingmounted thereon the upper` apertured collar portion 80 -of a link 81 ofwhich the lower apertured end portion 82 is provided with a -hollow'boss .member S3 pivotally received within an aperture S4' provided inthe ,projecting end S5 of a crank member'86. AIt will also be observedthat the upper end porti-on of 'the .link 81 and its projecting collar'80 are freely disposed within an arcuate slot '87 formed intheendportion of the crank 86, which slot 87 functions as aguide for thecollar 80.

Referring particularly to Figs. 4, 7 and 10, the end portion 88 of thecrank 86 is keyed upon a shaft S9 journaled in a bracket portion 1S ofthe sewing 'machine frame 1:5, which shaft 89 has keyed upon its otherend .portion a segment gear 90 which meshes with a second segment gear91 mounted upon a second crank member 92 which is pivotally mounted uponthe bracket 15 about the .longitudinal axis of a supporting bolt 93.From this Vit vwill be understood that by moving the second crank 92 upVand down the segment gear 91 will rotate the segment gear 90 to the endthat the first crank 86 will be oscillated .about the axis of itsmounting shaft 89 to the endthat the -slide block 63 will be shiftedlengthwise of its rocker- 75 arm 53 through the medium of the link 481.Further- --.inore, this movement Aof the .slide block 63 will functiont-o shift the end of the link 67 toward and away from the axis of therocker to the end that the amplitude of the feed and return movements ofthe auxiliary feed-bar l 29 will be decreased or increased accordingly.In this connection, the present mechanism is designed in a manner suchthat with the slide block 63 at a position near the 4base portion ofthefarm 5'8 `the auxiliary feed 'bar 29 will be given aback and forthmovement which will eX- actly coincide with 'that of the main feed-barZSto 'the end that ynogathering feed will result. However, asthe slide'blockis moved to its fullest extent toward the base of thearm 158-the'timing-of the back and forth movements of the auxiliary feed-bar29 willbe such that a stretching of the work will occur because of thedifferential movemen-t between the feed-bars 28 and 29. By the sametoken as the slide block 63 is moved outwardly ialong the crank arm l15Sthe amplitude of the feed and return movements of. the auxiliaryfeed-bar 29 will increase to the end 'that agathering feed action willresult.

Referring particularly to Figs. 4, 8 and 10, it is to be observed thatthe lshoulder portion'95 of the segment gear is provided Withaspring 96of which one end is locked labout a ylock screw-197 fastened to the.bracket 15 while the other end is locked as lat 98 to the segment gear9,0 to the end thatfthe spring will. urge the segment gear 90 to turn ina counterclockwise direction'as viewed in Fig. 8. In other words, thespring 96 will effectively urge the slide block 63ffto moveina directiontoward the base portion of the segment arm 58. l y,

Referring particularly to Figs. 4 and `8, the free end portion of thesecond crank 92is provided with a .notch 99 for lreceiving a chain 100which may be connected in aconventionalmanner -to a foot tread'le sothat the operator may manually .shift .the slide block 63 back and forthto produce various degrees of diierential feeding movement between vthe.main and auxiliary feed-bars 28 and 29. In this connection it is to beunderstood that the spring 96 operates lin a manner such as to urgeconstantly the free end portion of the crank 92 in an upward direction.

The free .end portion of the crank 92 operates up and down in a chamberformed between two spaced opposing Walls 101 and 102 of the sewingmachine frame, which walls have aligned vertically disposed slots 103and 104.

Positionedwithin these apertures 103 ,and 104 are a pairv of bolts 10Sand 106 each carrying a sleeve 107 having a skirt .108 whose diameter isgreater than the width of Ythe slot 104. A nut 109 is positioned on eachof the bolts and 106 .and is located within a recess 110 'formed behindthe slot 104. From this it will .be appreciated that each of the boltsmay be backed away from its associated nut 110 so as to permit theAbolts to be adjusted lengthwise of the slot 104 to any desiredposition, `and thereafter the bolt may be retightened so that the .nut`110 and its associated skirt 108 will function to lock the bolt in anydesiredposition of adjustment. From this it will vbe understoodthat theybolts 105 and 106 function as adjustable stops toarrest the upward anddownward movements of the crank 92 to the end that hetoperator mayadjust the .upper and lower limits of the movement of the slide block63. If desired, indicia 111 and numerals may beprovided upon the face ofthe frame 'wall 101 to show the operator the amount of differential feedadjustment effected by the movements of the crank 92. k

Having thus set forth the nature of the invention, what we claim hereinis:

1. Differential feeding mechanism fork a sewing machine, comprising, a.main .rotary shaft, a plurality of eccentric elements carried upon saidshana pair of feed kdog carriers supported .for voscillatory vandreciprocatory movement with each-carrier embracing anfeccentric element-so as to' be oscillated thereby, a pitman lhaving `one end thereofembracing one of said eccentric elements and its other end connecteddirectly with a rst of said carriers for imparting reciprocatorymovement thereto, a rocker pivotally mounted about a xed axis, meanspivotally connecting one of said eccentric elements with said rockerthereby to oscillate said rocker about its axis, means separate fromsaid last mentioned means slidably connected with said rocker andpivotally connected with the second of said carriers for impartingreciprocating movements to such carrier, and manually operable means forshifting the slidable connection between said last mentioned means andsaid rocker thereby to vary the amplitude of reciprocatory movementimparted to said second carrier by said rocker.

2. Differential feeding mechanism for a sewing machine, comprising, amain rotary shaft, a plurality of eccentric elements carried upon saidshaft, a pair of feeddog carriers supported for oscillatory andreciprocatory movement with each carrier embracing an eccentric elementso as to be oscillated thereby, a pitman having one end thereofembracing one of said eccentric elements and its other end connecteddirectly with a first of said carriers for imparting reciprocatorymovement thereto, a rocker pivotally mounted about a fixed axis, meanspivotally connecting one of said eccentric elements with said rockerthereby to oscillate said rocker about its axis, means separate fromsaid last mentioned means slidably connected with said rocker andpivotally connected with the second of said carriers for impartingreciprocating movements to such carrier, manually operable means forshifting the slidable connections between said last mentioned means andsaid rocker thereby to vary the amplitude of reciprocatory movementimparted to said second carrier by said rocker, and manually adjustablemeans associated with said manually operable means for arresting themovement thereof in various selected positions.

3. Differential feeding mechanism for a sewing machine, comprising, amain rotary shaft, a plurality of eccentric elements carried upon saidshaft, a pair of feeddog carriers supported for oscillatory andreciprocatory movement with each carrier embracing an eccentric elementso as to be oscillated thereby, a pitman having one end thereofembracing one of said eccentric elements and its other end connecteddirectly with a rst of said carriers for imparting reciprocatorymovement thereto, a rocker pivotally mounted about a fixed axis, meanspivotally connecting one of said eccentric elements with said rockerthereby to oscillate said rocker about its axis, means separate fromsaid last mentioned means slidably connected with said rocker andpivotally connected with the second of said carriers for impartingreciprocating movements to such carrier, spring means biasing theslidable connection between said last mentioned means and said rockertoward the axis of rocker oscillation thereby to produce a minimumamplitude of reciprocatory movement of said second carrier, and manuallyoperable means for shifting the slidable connection relative to saidrocker and away from the axis of rocker oscillation thereby to produceincreasing increments of reciprocatory movement of said second carrier.

4. Dilerential feeding mechanism for a sewing machine having a frame,comprising, a main rotary shaft, a plurality of eccentric elementscarried upon said shaft, a pair of feed-dog carriers each embracing atits front end portion one of said eccentric elements so as to beoscillated thereby, a support carried by said frame and engaging therear end portions of said carriers for supporting such end portions andforming an axis common to both carriers with reference to which axis thecarriers have pivotal and longitudinal movements, a pitman having oneend thereof embracing one of said eccentric elements and its other endconnected directly with a first of said carriers for impartingreciprocatory longitudinal movement thereto, a rocker pivotally mountedabout a fixed axis, means pivotally connecting one of said eccentricelements with said rocker thereby to oscillate said rocker about itsaxis, means separate from said last mentioned means slidably connectedwith said rocker and pivotally connected with the second of saidcarriers for imparting reciprocating movements to such carrier, andmanually operable means for shifting the connection between said lastmentioned means and said rocker thereby to vary the amplitude ofreciprocatory movement imparted to said second carrier by said rocker.

5. Dilerential feeding mechanism for a sewing machine, comprising, amain rotary shaft, a plurality of eccentric elements carried upon saidshaft, a pair of feeddog carriers supported for oscillatory andreciprocatory movement with each carrier embracing an eccentric elementso as to be oscillated thereby, a pitman having one end thereofembracing one of said eccentric elements and its other end connectedwith each of said two carriers for imparting reciprocatory movementthereto, and manually operable means interposed between said pitman andone of said two carriers for creating selective amplitudes ofdifferential reciprocatory movements between said two carriers.

6. Differential feeding mechanism for a sewing machine, comprising, amain rotary shaft, a plurality of eccentric elements carried upon saidshaft, a pair of feeddog carriers supported for oscillatory andreciprocatory movement with each carrier embracing an eccentric elementso as to be oscillated thereby, a pitman having one end thereofembracing one of said eccentric elements and its other end connecteddirectly with a first of said carriers for imparting reciprocatorymovement thereto, a rocker pivotally mounted about a fixed axis, meanspivotally connecting said pitman with said rocker thereby to oscillatesaid rocker about its axis, means separate from said last mentionedmeans slidably connected with said rocker and pivotally connected withthe second of said carriers for imparting reciprocatory movement to suchcarrier, and manually operable means for shifting the slidableconnection between said last mentioned means and said rocker thereby tovary the amplitude of reciprocatory movement imparted to said secondcarrier by said rocker.

7. Differential feeding mechanism for a sewing machine, comprising, amain rotary shaft, a plurality of eccentric elements carried upon saidshaft, a pair of feeddog carriers supported for oscillatory andreciprocatory movement with each carrier connected with an eccentricelement so as to be oscillated thereby, a pitman having one end thereofembracing one of said eccentric elements and its other end connecteddirectly with a Iirst of said carriers for imparting reciprocatorymovement thereto, a rocker pivotally mounted about a xed axis, meanspivotally connecting said rst carrier with said rocker thereby tooscillate said rocker about its axis, means slidably connected with saidrocker and pivotally connected with the second of said carriers forimparting reciprocating movements to such carrier, and manually operablemeans for shifting the slidable connection between said last mentionedmeans and said rocker thereby to vary the amplitude of reciprocatorymovement imparted to said second carrier by said rocker.

References Cited inthe tile of this patent UNITED STATES PATENTS

